Crashing when switching to cycles
This fixed the error for me (taken from another thread): 
Turns out my WIndows Update was to blame, installing a .dll file that was breaking both Maya and Blender. This was called igdrclneo64.dll/igdrcl64.dll.  It’s located in C:\Windows\System32 (On my computer it was located in C: \ Windows \ System32 \ DriverStore \ FileRepository \ igdlh64.inf_amd64_250db833a1cd577e.) I moved it to the desktop and now everything works